Servo-motor



June 28,1938. A. A. HODGKINS' 2,121,874

SERVO-MOTOR original'Filed April 9, 1931 INVENTOR ALBERT A. H006K/NS BY Q g ATTORNEY a fmo'tonboat what. iscommonly known as a rver'se ge'ar so constructed thatthe operator of thieboat by means 9f a control lever may set the u j SERVO-MOTOR.

Ame ia} Harmeree I itoUniverSalfGear shift Corp ation; N w Y rk; N.Y .,"aeorporation of Delaware Hi ,'I., assi nor ,ioriginal application iApril 9; -\131;'? Serial;No2

528,840,- now Patent,No.. .2,023;22a, dated Deinvention relatesfto control or reverse gearing and more .particularlyito reverse gearing of the type ordinarily used infconnection I Withfmarinfe engines; such as motor boat engines and the like. It is usual to providein the drive mechanism between the enginev and propeller of ga igforlforward drive, for neutral in which position' the engine idles-without actuating theproipelljerjor for'reverse drive as is desired.

In" many instances an r particularly inthe cabin type of boats} the engine is often placed beneath the floor of the bridge declgand asystem ofllevers andlinks 'ponnects the reverse gear mechanismwith a control standor box on the. bridge deck so thatthe gear maybe controlled from'this' point. When control of thegear is effected irom' a re rnotejpoint in this way, there-1 sul't is'that'theconnections-will naturally ofier 1 some;r esistang-e to the m ovement of the control 7 lever dueto their weight and to" friction between tion, the connections between the control lever and the reverse gear must be disposed in more or less of adirect line and cannot always be placed in positions where they will not interfere with the use of the boat.

' One'object of the invention is to provide a controlling device for reverse gearing which may be operated with great facility and which will require the exertion of very little energy on the part of the operator;

of'a control mechanism for reverse gears which may be operatedby fluid pressure, and preferably J are manually controlled.

Another object of the invention is to provide a novelremote control'actuating device for a gear mechanism such that-'the'device will operate posi- 1 tively and efiiciently and the mechanism of which.

may be mounted within a relatively small space 'and in such locations that no obstructions will the moving parts, and the shifting of the control I lever is attended with somedifiiculty. In addi- Another object of-the invention is the provision will be pneumatically operated by means of rec mber 3,. 1935. Divided ahd this application f gctober'll, 1935, Serial hid-45,2495 v These and other objects of the invention and V the means for their attainment will be more a.p-.-v I parentfrom the following detailed specification, taken inconnection with the accompanying drawing illustraltingone embodiment by which the invention maybe realizedand in which the actuating cylinder and piston are shown'in longi: tudinalgyertical section for controlling the reerse arin fIgf illustrate a preferred embodiment of inventiom l have shown'in the drawing'a portion of a power source such as an internal combustion engine provided with a housing l3 within'which is locatedj the. usual reverse gear mechanism.

Projectingirom this housing is a rock shaft I4" upon which is secured a rock arm l5. It will be understood that, as is usual in the construction of such devices, the rock arm [5 will have a neutral position wherein the propellerwill not be actuated bythe engine and that when the arm is;rqckedin one direction from this position, such s-91 nstance; t he l a wn e rop er. will be turned in such a direction as to drive the boat ahead, and when moved from the neutral position to the right, as shown, the directionof thekpropeller will be reversed. Asshown; the neutral position will obtain when the rock'arm I5 is in a substantially upright position, although this arrangement may be varied as desired.

The arm I5 is provided at its upper end with 1 a slot l6 within which loosely rests a pin l'l carried by a piston rod l8, which rod projects from position, .the arm l5 will be rocked to the right orleft, as shown. The cylinder'lil may be sup ported upon the'gear housing l3 by means 01' a bracket I93.

. At one end of the cylinder is provided a hollow boss 2| within which is a thimble 22 surrounding the piston rod l8, the end of which thimble'acts as a stop for'aspring shoe 23. This spring shoe with it by the shoulder 26 provided at the end of the reduced portion 25.

Secured at one end of the cylinder is a supporting plate 21 through openings in which pass a number of bolts 28, the bolts having secured upon their ends a plate 29. The oppositeends of the bolts are provided with enlarged heads understood, however, that the plate 29 will be moved to the right by the piston when the latter position shown, and at this time the bolts 18 secured to the plate 29 will'move to the right through the openings in the plate 21 into the hollow portion 33 of the boss 2l. The spring 3| passes freely through an opening 34 in' the plate 2'? so that its end bears against the shoe 23. The ends of the cylinder l9 are provided with fluid passages 35 and 36 which are connected respectively with tubes or pipes 31 and 38, by

which fluid underfpressure or vacuum may be introduced into the cylinder upon either side of the piston;

It will be understood that the spring 3| tends,

' to maintainthe piston in the position shown in the drawing, and will so maintain the piston except when the force of the spring is overcome by theiorce of fluid pressure within the cylinder.

with a source'of vacuum or reduced air pressure,

and. the pipe 38 is vented to the atmosphere, the piston Ellwill movetothe right, as shown, against the action of the spring and will compress the "into the chamberS-B. If, now, the pipe 31 is vented to the atmosphere, the spring will re-' turn the piston to its original position. When the pipe 38 is in communication with a source pi reduced air pressure and3'l vented to-the atrnosphere the piston will be moved to the left from its intermediate position. During this movement the shoulder 26 on the piston rod picks ber 3, 1935.

:,;moves in this direction fromthe intermediate If, for instance, the pipe 31 is in communication 7 spring against "the shoe 23, the bolts 28 moving up the shoe fi and compresses the spring against the plate ZQwhi h is held against movement to the left by thebblts 28, and the spring is thus compressed in the-.Qpposite direction so as to again return the pistoirjo to its intermediate position when the pipe'3 is\vented to the atmosphere.

Thi'sfapplication is a divisional-application of United States Patent No. 2,023,229 dated Decem- Various modifications will occur tdfchose skilledin'the art in the configuration, composition and'disposition .of the component elementst going to make up-the invention as a whole as well as in the use to which the invention is put, and no limitation is intended by the phraseologyof the'foregoing description or illustrations in the accompanying drawing, except as indicated inthe appended claim.

What is claimed is:

I Pneumatic controlling means for a gear mechanismcomprising a cylinder, a piston movable thereim a' piston rod connected to the piston and operatively' connected with the gear mechanism, a 'spring surrounding the piston rod within the; cylinder; an abutment for the spring mounted at the end thereof adjacent the piston, a second abutment mounted at the other end of the spring, bolts connected with thefir st named abutmentand guided for sliding movement,'and means for effecting movement of the first abutment by the piston when it is moved in one direction, means carried with the bolts to limit movement of said firstabutmentin the opposite direction, means efiecting movement of the other abutment by the piston rod when the piston is moved in the other direction, andmeans to limit movement of said second named abutment in the opposite direction, the movement of saidabutments acting to tension the spring to centerwthe'pistonafter itsmovement in either direction. V

' r 'j ALBERT A. HODGKINS. 

